What Causes Brown Discharge And Bleeding After Taking Elleste Duet Conti?

hi , last year i was put on elleste duet but my periods came back every month so my doc put me elleste duet conti but in the 4 wks i have been on them i have had constant heavy brown discharge and occasional bleeding should i go back 2 docs as on intenet it says can take a while 2 settle down but after 4 wks i"ve had enough